Robin Van Persie's 24 goals fired Manchester United to their 20th league title but manager Alex Ferguson was quick to praise the contributions of some of his unsung heroes.

Michael Carrick consistently held the midfield together with calm assurance and young defenders Rafael and Phil Jones were singled out Ferguson as players who have made huge strides.

"You saw this season an incredible improvement in the boy Rafa," Ferguson said as the celebrations kicked off at Old Trafford following Monday's 3-0 win over Aston Villa.

"He has had a fantastic season. His impetuosity has left him and he's playing with great maturity now. As the season has progressed, he has developed fantastically well.

"I think Jones might be one of the best players we have ever had, no matter where we play him. He has that drive about him and I think at 21 years of age he is going to be a phenomenal player. I think he can play anywhere on the pitch."

Rafael has excelled in coming forward with bursts of speed and skill to supply pinpoint crosses or breathtaking goals such as the spectacular piledriver in the 2-0 win at Queens Park Rangers.

Jones, though dogged by injury problems, displayed power and composure in defence or as a man-marking midfielder.

Shinji Kagawa, United's other big signing last year, has shown glimpses of the brilliance which triggered his move from Borussia Dortmund, while the seemingly ageless Ryan Giggs and dynamic Danny Welbeck also played their part.

United's run of 27 league wins in 34 games could not have been achieved without the contributions of Carrick, goalkeeper David de Gea and Wayne Rooney.

OCCASIONAL BLUNDERS

Despite occasional blunders when handling crosses, the 22-year old De Gea has been a pillar of strength between the posts and United ground out many results thanks to his superb shot-stopping and reflex saves.

Described recently by his captain Nemanja Vidic as "the glue that holds it all together," Carrick once again made the holding midfielder slot his own among a group of players often touted as more talented.

Few would dispute that Carrick lacks the guile and creativity of world-class central midfielders like Barcelona's Xavi, but he pulls the strings with neat passing, intelligent positional play and an uncanny ability to create space.

Rooney did not enjoy one of his best seasons but still scored a healthy 12 goals often from deeper positions.

Shifted across the front line to play in deeper roles behind Van Persie and at times deployed in central midfield, Rooney again sacrificed his personal interests for the greater good as he did when Cristiano Ronaldo led United's charge.

The bulk of the plaudits, however, will go to former Arsenal striker Van Persie, whose lethal finishing fuelled United's challenge.

"I think Van Persie was such a great player for Arsenal that when he came available ... when you identify that a great player is coming to the end of his contract, and you feel like United should go for him, it doesn't matter what position it is," Ferguson said.

"In this case, it was a striker and he has made a fantastic contribution to the season."